On the 9 May 2016 Mercury passed directly between the Sun and Earth. With the use of a special filter I was able to have some excellent views of the event and capture some nice images. There are two groups of sunspots near the centre of the disc, one much more obvious, as well as the crisp round disc of Mercury in this picture taken about a fifth of the way into the transit.
This animated image shows the first few minutes of the transit. First contact is just before the planet becomes visible, second contact is when it fully enters the sun's disc. The exact times depend on the type of equipment used as the sun appears larger when imaged in some narrow bands of light. The stretching and shifting of the image is caused by atmospheric turbulence. The earlier image is sharper because it is a stack of several images that average out this distortion.
The second photo is from near the middle of the transit, when Mercury appeared closer to the two sunspot groups. remeber, although it looks like it is on the surface, Mercury's orbit takes it between abjust over half to about 2/3rds of the way from earth to the Sun.
This is the equipment I used, nothing particularly expenxsive, but note the silver Baader solar film filter, just visible inside the end of the telescope. this reduces the sun's glare by about 99.99% Remember, looking at the sun without proper equipment will cause eye damage and even blindness.
It's even dangerous to use a small finder scope on the sun, so instead I made this special solar finder that uses a pinhole to project an image onto a small screen.